I expect the IRIS-T has longer range than the RBS-70, because just the missile (87kg) weighs as much as the RBS-70 system (stand+sight+missile) (87kg). Wonder if the new system will be a vehicle mount or towed, because it certainly isn't be man portable!

Usually you get more range firing a missile from a platform air-to-air than surface to air. It's worth noting the given range of air IRIS-T is ~25 km.
Though the IDAS (navalized version of IRIS-T) has a declared range of ~20 km, and if the land version of IRIS-T has similar performance to IDAS, a 5 km range penalty isn't bad at all.